Fundamental study on protein changes taking place during malting of oats

During the malting process, storage proteins are degraded by proteolytic enzymes into small peptides and amino acids. The activity of these enzymes was measured during malting of oats and was found to be increased. To quantify proteolytic degradation, proteins of unmalted, germinating and malted grains were fractionated. After extracting the oat proteins (Osborne fractionation), protein fractions were analysed using a Lab-on-a-Chip technique, which separates the proteins - based on their molecular weight - by capillary electrophoresis. This new technique for the analysis of proteins was supported by using two-dimensional gel electrophoresis. In addition, amino acid analysis was carried out. In general a degradation of proteins to small peptides and amino acids could be observed in the globulin, prolamin and glutelin fractions. In the albumin fraction a protein increase was observed, which is due to the fact that this fraction contains the majority of the metabolically active proteins. Amino acid analysis supported the observation of increased protein amount in the albumin fraction and decreased protein amounts in the other fractions. Some proteins, which have not been described in the literature, were detected in the albumin and glutelin fraction, since Lab-on-a-Chip technique allows detection of proteins with low molecular weights of 4.5 kDa. (C) 2008 Elsevier Ltd. All rights reserved.